With the advent of PVC and similar piping systems, the installation and maintenance of piping systems has generally been made much easier and less costly. Such piping systems are commonly used in lawn sprinkler and similar applications. Unfortunately, there are several significant problems with these systems that still remain. One such problem is the installation, and especially replacement, of control valves associated with these systems.
In many water systems, a water valve or similar control is provided in-line along a run of piping. The water valve generally has a rigid housing defining an inlet and an outlet and is arranged to control the flow of water from the inlet to the outlet. The inlet and outlet may comprise smooth passages for receiving a pipe therein, or comprise an internally or externally threaded passage for connection of a rigid adaptor for connection to a pipe.
Removal of such a valve is quite easy, since the PVC piping may be easily cut. Generally, the piping is cut some distance from the inlet and outlet of the valve and then the valve is removed, leaving exposed pipe ends.
Installation of a new valve is then difficult. In order to install a new valve, the valve and a combinations of fittings and pipe extensions must be connected to span the space between and connect the two pipes. No matter what the configuration of components, however, because the components are arranged to engage in a slip-fit or other overlapping arrangement, at some point during the installation the problem arises that the distance between the pipe ends is less than the total length of the components which must be installed therebetween.
For example, in a common installation method, an adaptor is connected to the inlet and outlet of the valve. A shunt pipe segment is then slipped into the port of each adaptor. Next, the ends of the shunt pipe segments must be connected to the exposed pipe ends. This is accomplished with a connector or such as a slip fitting. A problem arises, however, in the fact that the shunt pipe segments and the exposed ends of the pipes must both be inserted or slip-fit into each connector by some distance in order for there to be no leaks or breaks. In other words, the straight-line distance between the ends of the shunt pipes extending from the valve along with the connectors is greater than the straight-line distance between the exposed ends of the pipe. This overlap distance may be on the order of 0.5 to 1 inch at each interconnection.
In a PVC pipe system, a common way to increase the distance between the components to be connected (for example the shunt ends of the pipes and their respective connectors) is to bend or flex the pipes. By bending both pipes so that they are not aligned, the distance between the last two components which must be interconnected to complete the installation may be increased. There are several problems with bending or flexing the pipe in order to mate or insert the pipe elements as described. A primary problem is that the piping is somewhat brittle and prone to breakage under bending stress. Thus, when a valve is replaced in a manner as described above, when the pipe is flexed, it may crack or break at another point along the system.
Another problem with the valve replacement method is that a substantial length of the pipe leading to and from the valve must be generally exposed in order to permit sufficient flexing. When the piping is buried, this may require digging up many feet of pipe. In a case where the piping is embedded in a wall, concrete or the like, substantial demolition and re-construction may be required.
Another problem is that the last two components may not properly seat when inserted at other than a direction of direct on-axis alignment. An adhesive is applied to an end of the pipe or other element to be inserted into the slip or other connector. When the pipe is inserted into the slip connector at an angle, the adhesive may cause the pipe to adhere to the slip connector before it is fully inserted therein and the pipes and other components are permitted to move into axial alignment. This may cause the connection to be weak and susceptible to leaks.
Although the above-described problems have been described with particular reference to PVC and similar plastic piping systems, it should be noted that similar problems arise when replacing a valve in other types of systems, such as those constructed from metal piping. In such systems, the option of bending the pipe to facilitate the connection may not be present, making the installation much more difficult.
It is desirable to provide a means by which a valve in a piping system may be easily installed and/or replaced, and which minimizes the number of necessary component parts.